| Na2EDTA•2H2O | 866.7 mg |
| FeSO4•7H2O or Fe2(SO4)3•nH2O |
2.28 mg |
| KOH | 866.7 mg |
| Milli-Q Water | ~100 mL |
- Dissolve KOH in 31 mL Milli-Q
- Add Na2EDTA•2H2O
- In separate container, dissolve FeSO4•7H2O or Fe2(SO4)3•nH2O in 60.67 mL Milli-Q
- Mix both solutions together
- Bubble filtered air through combined solutions until the color darkens (~2.5 hr)